atoms are made of 3 types of sub atomic particles; neutrons, protons and electrons
atomic number is the number of protons which is characteristic for the element. Atoms of the same element have the same number of protons.
mass number is the sum of the neutrons and protons.
Isotopes are atoms of the same element with different mass numbers. since they are the same element number of protons are the same but number of neutrons vary.
therefore 2 isotopes are of the same element so they have the same number of protons.
I think the correct answer from the choices listed above is option D. When a molecular compound melts, they undergo the process of phase change from solid to liquid therefore m<span>olecules arranged in a regular pattern change to an irregular pattern. Hope this answers the question.</span>
